Medical Device Daily Associate

PARIS – A majority of the estimated 10,000 attendees crammed into the Palais de Congr s for the EuroPCR 2005 meeting gathered together to attend a late-breaking clinical trial session that had a decided focus on the current hot topic du jour, that of drug-eluting stents (DES).

In two presentations, follow-up studies for Boston Scientific’s (Natick, Massachusetts) Taxus Express2 paclitaxel-eluting stent were released for the first time.

Neil Weisman, MD, director of cardiac ultrasound and ultrasound core laboratories at the Cardiovascular Research Institute at Washington Hospital Center (Washington), said that follow-up results from TAXUS V study, using ultrasound within the vessels, showed improvement in patients with small vessels, large vessels and severe blockages requiring multiple, overlapping stents, compared with a control group.

The TAXUS V study, which involved 1,172 patients at 66 sites in the U.S., represents the most complex patient and lesion cohort yet subjected to a blinded, randomized, controlled trial: total length 28.4 mm, 2.25 mm stents in 17.6%, 4.0 mm stents in 17.5%, multiple stents in 32.8% and 30.8% of diabetic patients.

In this complex patient population, the slow-release, polymer-based Taxus stent was safe, with low rates of death, MI and stent thrombosis at 30 days and nine months compared to control, and was very effective – with marked reduction in clinical and angiographic restenosis.

“The lesions studied in TAXUS V are some of the most difficult we confront in interventional cardiology,” said Weissman. “The TAXUS V IVUS data provides an especially rich source of information on the excellent performance of the Taxus system. The uniform neointimal suppression across both single stents and multiple overlapping stents attests to the efficacy of Taxus across a wide range of lesion lengths.”

The company previously disclosed in March that the trial met its primary endpoint of nine-month target vessel revascularization (TVR), as well as all secondary endpoints.

In a second Boston Scientific study called TAXUS VI, which evaluated the moderate-release version of the Taxus stent, a continued reduction in the rate of repeat procedures was demonstrated after two years in 428 patients. The rate of patients living free of serious complications was 90.3%, vs. 79% for the bare-metal stent control group.

In the randomized, double-blind trial, lesion size ranged from 18 mm to 40 mm in length and 2.5 mm to 3.75 mm in diameter.

Safety and efficacy benefits were maintained at two years, and even with a dosing rate eight to 10 times higher than the slow-release stent, there was no compromise in safety.

The results were presented by Eberhard Grube, MD, of the Heart Center (Siegburg, Germany).

According to Grube, TAXUS VI is the first clinical trial to support durability of drug-eluting stents in complex lesions at two years. Clinical follow-up included more than 95% of the patients enrolled at two years (428 out of 446).

“The two-year data from TAXUS VI clearly demonstrate the sustained safety and efficacy of the moderate-release TAXUS paclitaxel-eluting stent system in the treatment of patients with long lesions treated with multiple, overlapping stents,” he said. “These data indicate that TAXUS stents offer sustained TLR benefits over time.”

Boston Sci launched the slow-release Taxus Express2 stent in the U.S. in March 2004. The moderate-release version of the stent hasn’t yet been approved for commercial distribution.

Rival stent maker Johnson & Johnson (J&J; New Brunswick, New Jersey), via its Cordis (Miami Lakes, Florida) subsidiary, also released positive data from two studies measuring the performance of its Cypher sirolimus-eluting stent in diabetic patients, who can be more difficult to treat because of smaller blood vessels.

In a study of 607 diabetic patients, called ARTS II, those receiving a Cypher stent had lower rates of major complications such as death, stroke and heart attack than diabetic patients who underwent bypass surgery in a predecessor trial called ARTS I.

Marie-Claude Morice, MD, head of cardiology at Institut Jacques Cartier (Massey, France) reported results from that trial.

J&J also released longer-term results from its RAVEL – RAndomized Study with the Sirolimus-eluting VELocity Balloon Expandable Stent – study that showed patients who received the Cypher drug-coated stent required fewer repeat procedures after four years than those receiving bare-metal stents.

Eduardo Sousa, MD, PhD, professor of interventional cardiology at Dante Pazzanese Institute (Sao Paulo, Brazil), presented results showing that 91.8% of patients with a Cypher stent were free of major complications including heart attack and death after four years, compared with 73.4% in the control group. Additionally, stent-related side effect rates including stent thrombosis and late stent thrombosis continued to remain at zero for Cypher stent patients.

“Since the first data from the RAVEL trial were released, the impressive initial clinical and angiographic outcomes from the study further supported with four years of clinical follow up, confirm the impressive safety and efficacy profile of the Cypher stent year after year,” said Sousa. “The four-year data provides physicians with further time-tested clinical evidence for using sirolimus-eluting stents to treat patients.”

A randomized study involving 238 patients in 19 centers across Europe and Latin America, RAVEL was the first double-blinded trial to demonstrate that a sirolimus-eluting stent virtually suppress post-stenting angiographic late loss at six months. In the study there was no restenosis or target lesion revascularization at the six month follow-up.